The present invention relates to electrodes used in cardiac stimulators.
One of the materials which is best suited for the manufacture of electrode tips for cardiac stimulators (that is the portion of the electrode which will come into contact with the cardiac wall) is pyrocarbon (or pyrolytic carbon).
This material, either pure or with the addition of small percentages of silicon, has indeed excellent characteristics of biocompatability, mechanical strength and lack of variation with time.
However, an electrode for cardiac stimulators having a tip of pyrocarbon would give rise to high bias voltages in use (that is a high residual electrical potential on the tip at the instant at which the stimulation current returns to zero after a stimulation pulse of the myocardium), which would give rise to a power loss in the cardiac stimulation operation.
The present invention has the object of forming a tip of "activated" pyrocarbon, that is free from the said disadvantage and hence usable to advantage as an electrode tip for a cardiac stimulator.